1. Field of the Invention.
This invention relates to cardiopulmonary resuscitation, and particularly to a portable apparatus applicable to massage the heart of a person whose heart has stopped beating.
2. Description of the Prior Art.
It is believed the prior art relating to this invention may be found in Class 128, sub-classes 90 and 28; and Class 434, sub-class 265.
A search for prior art has revealed the existence of U.S. Pat. Nos. 1,918,546; 2,036,371; 2,484,306; 3,254,645 and 4,338,924.
U.S. Pat. No. 1,918,546 is directed to an artificial respirator, and does not appear to include apparatus for massaging the heart.
U.S. Pat. No. 2,036,371 is also directed to artificial resuscitation, and teaches a device that applies pressure downwardly and forwardly and then upwardly and rearwardly to inflate the lungs.
U.S. Pat. No. 2,484,306 relates to respirators used to revive a drowning victim, or a victim whose breathing has been interrupted. This patent, as with U.S. Pat. No. 1,918,546, describes a structure including a framework which supports a ram that is spring-pressed in an upward direction, but which may be forced downwardly against the spring pressure by a cam operated by rotation of a handle, to effect compression and expansion of the lungs.
U.S. Pat. Nos. 3,254,645 and 4,338,924 are the only two patents found that relate specifically to heart massage devices. However, both these patents teach structures that are significantly different from my invention in both structure and mode of operation.
In one aspect, this invention relates to heart massage, and in another aspect, functions to activate a respirator to provide for both circulation of blood and oxygenation of the blood being circulated.
It is well known that the heart and lungs work in unison to circulate and oxygenate the blood stream. The performance of both these functions simultaneously has been labeled cardiopulmonary resuscitation. The term has been abbreviated to CPR, and classes in CPR are regularly given throughout the United States. The term "cardio" of course refers to the heart, and "pulmonary" refers to the lungs. CPR of course includes mouth-to-mouth breathing, but may also include artificial respiration as performed by a mechanical respirator. Whether respiration is assisted by mouth-to-mouth breathing, or by a mechanical respirator, it is apparent that respiration aid should be accomplished in concert with chest compressions to massage the heart when the heart has stopped beating. Accordingly, one of the objects of the present invention is the provision of a mechanical heart massage apparatus that selectively operates in conjunction with or without artificial respiration efforts.
When a person's heart stops beating, blood stops flowing in the body, particularly to the brain, and it is known that the lack of a supply of oxygen to the brain for only a very short time can cause permanent damage to that organ. It is therefore imperative that heart massage be initiated without delay. Accordingly, another object of the invention is the provision of a heart massage apparatus that can be applied to a person and activated in an extremely short interval of time.
Literature on the subject of CPR is explicit regarding the repetition rate of chest compressions for adults, children and infants. The diffuculty is that few people in the position of a rescurer have read the literature, and fewer people have practiced CPR so as to learn the desirable techniques. Accordingly, a still further object of the invention is the provision of a heart massage apparatus which may be easily and quickly applied to a victim of any size and age, and which may just as quickly and easily be adjusted to accord with the recommended chest compression rate and extent for the particular victim involved.
Victims to whom heart massage has been administered by hand sometimes receive injuries because of poor technique including improper placement of hands, improper application of pressure, distribution of pressure over too large an area, insufficient chest compression or too much chest compression. Accordingly, another object of the invention is the provision of an apparatus which may quickly be strapped onto a victim's chest at precisely the proper position, and adjusted to effect just the right amount of chest compression at the recommended repetition rate.
Heart massage is conventionally administered with the victim lying on his back on a hard surface. The literature on the subject cautions against administering heart massage while the victim is lying on a soft surface, such as a bed. The reason for this caution is that heart massage proceeds by compression or squeezing of the heart between the sternum (breast bone) and the back bone or spine. It is said that if the back bone is not supported on a hard surface, i.e., one that will not yield, then compression of the chest cannot be effected. It is therefore an important object of this invention to provide a heart massage apparatus that will function to compress the chest even if the victim is lying on a soft support and continue to apply rhythmic heart massage even while the victim is transported or moved from one location to another.
The amount or extent of chest compression varies depending on the size and age of the victim. Thus, for most adults, the recommended chest compression is about 11/2 to 2 inches. For a child, 3/4" to 11/2", and for an infant 1/2" to 3/4". The repetition rate of chest compression also varies, depending on size, age, and whether there are one or two rescuers involved in the procedure. Where a single rescuer is involved with an adult victim, the recommended repetition rate is 80 compressions per minute. If two rescuers are present, the rate drops to 60 per minute. For a child, 80-100 compressions per minute are recommended, while for an infant 100 compressions per minute are recommended. Obviously, even where two rescuers are present, given the trauma and anxiety present in the circumstances, it is most difficult for a rescuer to apply the requisite amount of pressure to achieve adequate chest compression and count the number of compressions per minute. Accordingly, it is a provision of the present invention to provide a heart massage apparatus that may be easily applied to any victim of any size, and which may easily be adjusted to provide the requisite number of chest compressions of the appropriate extent.
In the administration of heart massage, it is important that, once started, there be no more than a five second interruption in the procedure. It is also important that the application of pressure be rhythmic and regular, and that either mouth-to-mouth breathing accompany the heart massage, or that some form of artificial respiration be provided. It is therefore another object of this invention to provide a heart massage apparatus that, once applied and started, will continue operating indefinitely and independently of the rescuer in a regular and rhythmic repetition rate, thus permitting a single rescuer to apply mouth-to-mouth breathing in unison with the heart massage apparatus.
Once a victim's heart commences beating on its own after heart massage, it is important to monitor the victim carefully so as to be ready to resume heart massage should the heart falter again. Accordingly, another object of this invention is the provision of a heart massage apparatus that is portable, that may be left strapped to the victim ready to resume heart massage if the need arises, yet which constitutes no impediment to other ministrations that might be imposed on the victim by other life support systems, such as a respirator or oxygen tent.
Rescue personnel are often ordinary people with no special training who find themselves in the predicament of having to render aid. Where the aid required is heart massage, the anxiety and apprehension of the rescuer may be particularly acute. Coupling this anxiety and apprehension with lack of knowledge can have a devastating effect not only on the rescuer but also on the victim. Accordingly, another object of this invention is to provide a heart massage apparatus which itself guides the rescuer to make the proper adjustments of the apparatus in relation to the victim to which it is being applied.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described, since it may be embodied in various forms within the scope of the appended claims.